Peocess of making paper



UNITED STATES PATENT oFFlcE."

anus o. PEABODY, or BOSTON, MASSACHUSETTS.

PROCESS OF MAKING PAPER, FIBER-BOARD, AND SIMILAR MATERIALS.

No Drawing.

To all whom it may concern:

citizen of the United States, residin at Boston, in the county ofSufi'olk and ommonwealth of Massachusetts, have invented certain new anduseful Improvements in Processes of Makin Paper, Fiber-Board, andSimilar Material s, of which the following is a specification.

In the usual process of making paper, fiber board or similar materials,the stock, which consists mainly of a mass of fibers, is first beaten ina heater in the presence of water, and the resulting pulp is then runinto a stuff-chest from which it is drawn in a continuous stream intothe -vat or tank of the machine in which the paper or fiber board is tobe formed, such machine being usually either of the cylinder or of theFourdrinier type. The proportion of water to fibrous stock in the beaterand in the stuffchest is ordinarily considerably less than theproportion of water to fibrous material in the tank or vat from whichthe stock is sup-' plied directly to'the cylinder or Fourdriniermachine. For example, a usual proportion of water to fiber in the beaterand stuffchest may be perhaps 20 pounds of water to one of fiber,whereas in the vat of the cylinder machine a usual ratio of water tofiber may be perhaps 50 pounds of water to one of fiber. Accordingly,before starting the flow of stock from the stuff-chest into the vat ofthe machine, when operation of the machine is to be begun, it iscustomar to place in the vat a quantity of water su ficient to increasethe proportion of water to fibrous stock to the requisite degree.

In the manufacture of certain kinds of paper, or fiber board, there isintroduced into the stock in the beater, stuff-chest or otherpreliminary container, some added material which may be colloidal orcementitious in its nature, the amount which is so Specification ofLetters Patent. Patented Apr. 26, 1921 Application filed October 23,1918. Serial No. 259,418.

having run off in the waste water. This method has two serious defects.In the first place, the product produced does not contain the intendedproportion of the added substance and does not have the qualities which1 t should have, and in the second place, there is a serious loss due tothe waste of the added material which is carried 013? in the wastewater. These defects are so serious that ithas been thought to beimpossible to ntroduce certain substances by placing them 1n the beater,although in other respects better results are so obtained, and instead,attempts have' been made to impregnate the product after it comes fromthe paper machine. This has proved wholly impracticable for reasonswhich need not be explained here.

My present invention, therefore, provides a method by which certainsubstances, some of which are colloidal, cementitious, or soluble intheir nature, may be mingled with the fiber in the beater, and the fibermay be gathered by a paper machine without loss of the added substance,the entire run of the machine being uniform in respect to the proportionof the added substance.

Furthermore, I find that it is frequently possible to use a differentadded substance in the tank of the paper machine than in the preliminarycontainer, particularly when the substance is colloidal owing to thefact that colloidal substances are not interpenetrable.

. While my herein described novel method is particularly applicable whenthe substance to be added is colloidal,'I do not limit myself to its usewith such substances. To make my method fully understood, I willdescribe the manner inwhich the manufacture of one kind of paper isactually performed. In the manufacture of this kind of paper, the addedsubstance is an alkaline cellulose thiocarbonate, the function of whichis to cement together the mass of fibers in the paper or board. preferto use this material in my process, but may also use other substances inlieu thereof, such as glue,

casein, or viscose. I

According to my process, I may load a. beater with 250 pounds .dryweight of a mixture of hemp, jute, wood or other fibers,

5,000 pounds of water, sizing material, coloring matter in any usualproportions, and

25 pounds of alkaline cellulose thiocarbonate. After the stock has beenthoroughly beaten in the usual manner and the several ingredientsproperly incorporated throughout the mass of fibers, the beater load isdischarged into the stuff-chest, where it may perhaps be mingled withcomparatively small additional quantities of water.

I now fill the vat of my cylinder machine with water, say, 2,400 pounds.

It will be observed that the proportion of the alkaline cellulosethiocarbonate to water in the stock in the beater, in the instanceillustrated, will be 200 pounds of water to 1 pound of thiocarbonate.The proportion of water to thiocarbonate in the stock in thestuff-chest, though perhaps somewhat larger, will not differ verymaterially. If, now, I begin to discharge the stock from the stuff-chestinto the vat of the cylinder machine and begin to operate the machine,during the first part of the run the proportion of water tothiocarbonate in the tank will be very much greater because of the largeamount of water in the tank which the stock meets and in which it isdispersed as it enters the tank.

I have found that the presence of this great excess of water inproportion to thiocarbonate in the tank during the early part of the runmakes it diflicult to retain the thiocarbonate upon the fibers as theypass from the vat upon the screen and are taken away to form thefinished board; and the result is that the first part of the run of theboard is very inferior in quality, because of the lack of thesecementitious materials.

I have found that this difliculty may be remedied by adding to the waterin the tank of the machine a colloidal substance, such, for example, asalkaline cellulose thiocarbonate, glue, casein or viscose. I prefer toput into the Water in the tank a sufficient quantity of such colloidalsubstance so that the water. will be brought to the same degree ofconcentration as the water in the stuff-chest. For example, in theillustrative run above mentioned, I should prefer to put into the 2,400pounds of water in the vat of the cylinder machine about 10 or 12 poundof colloidal substance. lVhile I prefer to bring the water in the tankof the machine to substantially the same degree of concentration as thewater in the stuffchest, nevertheless good results may be obtained byusing less or greater quantities of colloidal substance in the tank; andmy invention is not limited to these proportions.

I also prefer to use as my colloidal substance in the tank the samematerial that is used in the heater to give the cementitious effect. Forexample, if I use alkaline cellulose thiocarbonate in the beater Iprefer to use alkaline cellulose thiocarbonate in the water in the tank,and if I use glue in the beater I prefer to useglue in the tank; butthis is-not necessary, and it is perfectly possible to use glue, forexample, in the tank when thiocarbonate is used in the beater, or viceversa.

By this method of operation I find that the cementitious material in thestock as it comes from the stuff-chest is not washed out or dissipatedwhen the stock enters the tank of the machine, but adheres tothe fibersas they pass from the tank upon the screen and appears in the finishedproduct, where it acts to cement the fibers together.

Sometimes it is desirable to add additional water to the stockas itleaves the stuff-chest or to the tank during the operation of themachine; and although I do not find that the addition of this waterinterferes with the proper functioning of the materials, I prefer to usefor this purpose, instead of fresh water, water that has drained offfrom the cylinder or the felts of the machine, since this reused watercontains some of the thiocarbonate or other cementitious materialsoriginally incorporated in it. This reuse of the water draining from themachine is not, however, essential to my invention.

If at any time during the operation of the machine the proportion ofcolloidal substance to water in the tank becomes less than the criticalamount necessary to prevent the washing out of the cementitiousmaterial, and it is found that the cementitious material is not beingretained upon the fibers as they pass from the vat, I fortify the stockin the tank by adding further quantities of colloidal substance to bringit up to the requisite proportion.

The product manufactured in accordance with my process is formed on thecylinder or Fourdrinier machine, or otherwise in any known manner, intosheets or other forms as desired.

What I claim as new and desire to secure by Letters Patent is 1. Theprocess of making paper which consists in introducing an added materialto a mass of fibers suspended in water in a preliminary container toform a stock of a predetermined standard of concentration with referenceto the added material, and forming the paper by means of a machine inwhich the fiber stock is further diluted but is maintained atsubstantially the same standard of concentration of added mate rial.

2. The process of making paper which consists in producing in apreliminary container a stock composed of fibers suspended in water,said stock containing an added material and being of a predeterminedstandard of concentration with reference to the addedmaterial, dilutingsaid stock and introducing more added material to restore preliminarycontainer to form a stock, and

the standard of concentration of said added material, and then formingthe paper.

3. The process of making paper which consists in producing in apreliminary container a stock composed of fibers suspended in water,said stock containing an added material and being of a predeterminedstandard of concentration with reference to the added material, andforming the paper by means of a machine in which the stock is dilutedand in which the standard of concentration is maintained by theintroduction of an added material which is different from that i whichis introduced in the preliminary container.

4. The process of making a product of the character described whichconsists in adding a cementitious material to a mass of fibers in apreliminary container to form a stock, adding a colloidal substance tothe water in the tank into which the stock is run and from which it issupplied to a machine for forming the product, and then forming theproduct.

' 5. The process of making a product of the character described whichconsists in adding a colloidal material to a mass of fibers in apreliminary container to form a stock, adding a colloidal substance tothe water in the tank into which the stock is run and from which it issupplied to a machine for forming the product, and then forming theproduct.

6. The process of making a product of the character described whichconsists in adding a cementitious material to a mass of fibers mingledwith water in a preliminary container to form a stock, and adding acolloidal substance to the water in the tank into which said stock isrun and from which it is supplied to a machine for forming the product,the proportion of colloidal,

substance added to the water in the tank being substantially similar tothe proportion of cementitious material to water in the stock before itis run into the tank, and

forming the product.

7. The process of making a product of the character described whichconsists in adding alkaline cellulose thiocarbonate to a mass of fibersmingled with water in a adding alkaline cellulose thiocarbonate to thewater in the tank into which the stock is run and from which it issupplied to a ing a colloidal substance to a massof fibers mingled withwater in a preliminary container to form a stock, adding a similarcolloidal substance to the water in the tank into which the stock is runand from which it is supplied to a machine for forming the product, saidcolloidal substance being added to the water in the tank insubstantially similar proportion to that which the colloidal substancebears to the water in the stock previous to its being runinto the tank,and forming the product.

10. The process of making a product of the character described whichconsists in adding a cementitious material to amass of fibers mingledwith water in a preliminary container to form a stock, adding acolloidal substance to the water in the tank into which the stock is runand from which it is supplied to a machine for forming the product,returning to the tank from time to time water reviously drained from themachine, and orming the product.

11. The process of making a product of the character described WlllChconsists in adding a cementitious material to a mass of fibers in apreliminary container to form "a stock, adding a colloidal substance tothe water in said tank at a percentage suflicient to prevent the washingout of the cementitious material, and forming the product.

In witness whereof, I'have hereunto set my hand in thepresence of twowitnesses.

v JAMES c. PEABODY.

Witnesses: I

' HARRISON F. LYMAN, GEORGE C. ABVEDSON.

